Multisensory and spatial processes in sensory substitution

Sensory substitution devices aim at compensating sensory deficits by converting stimuli coming from a deficient sensory modality (e.g., vision) into stimuli accessible through another modality (e.g., touch or audition). Studies conducted with these devices revealed the central nervous system to be very plastic. Various laboratories have conducted studies investigating such plasticity by means of behavioural and brain-imaging techniques. At the ISIR Laboratory, we focused on the factors underlying the learning of sensory substitution devices, their adequacy to the target population, and we explored ways of improving their design by the use of crossmodal correspondences and by taking into account individual differences in the used reference frames. We also investigated the nature of the experience with sensory substitution. In particular, we suggested moving beyond positions reducing experience to that of a single sensory modality. Rather, sensory substitution is considered as a multisensory experience, involving not only visual, but also auditory or tactile processes as well as cognitive processes. In this framework, individual differences do have an influence on the extent to which the different sensory modalities influence the experience with the devices.